With just the main PA rail AC supply connected, no load,sometimes at switch on will draw sustained >2 amp , so quickly switched off. At 50% mains , sustained 1 amp draw until switched off. Mains Tx ok on its own. DVM-D cold testing of PA devices and bridge rect etc check out reasonable. What to look for cold initially? I may try hot test again with the speaker output pcb disconnected as speaker protector thtristors on there. Initially one output channel failed soon after power up, which could be sp prot failure presumably, mains fuse did not blow though but that >=500W would be going somewhere it shouldn't. Perhaps another 50% mains half second try out and see if a thyristor is hot.
- posted
7 years ago